Created attachment 14126 [details]
Considering I'm in one page with a NavBar and ScrollView with 1 button and 30 labels. And I touch the button to open another page without NavBar. When I touch BACK, it comes back to the former page, but the bottom labels (28...) doesn't show.
Apparently it considers that we still don't have the NavBar and calculates the screen height wrong.
If I force "NavigationPage.SetHasNavigationBar(this, true);" in the first screen (OnAppearing method), it still doesn't work, but if I call " NavigationPage.SetHasNavigationBar(this, false);" and then "NavigationPage.SetHasNavigationBar(this, true);", it works.
I believe that Xamarin.Forms isn't considering that this value changed and for this reason, it doesn't recalculate the screen height. If I force the value to change (to false, and then true), the value changed is called and it works.
Issue happens only on iOS and I was able to reproduce in all versions (2.0, 1.5.2 and 1.3.5).
BTW, if I use the workaround approach (set to false, then true), it works fine on iOS8+, but on Phones iOS 7.1.2 it hides the NavBar and then shows it very fast. On iOS8, this behaviour can't be noticed by the user.
When do you intend to fix it?
Hi, any news about it?
We confirmed the issue and are working through our lengthy backlog. We haven't lost track of this issue! Thanks for reporting it.
Can this please be given higher priority?
Created attachment 23669 [details]
Sample showing issue
Added a more up to date sample.
When you push to a different page, and go back, you can see that the height is calculated wrong, because the last image on that page is now under the tabbar.
If you add the workaround, when you pop the page, the first page's content animates when it corrects it self, and doesn't look professional.
Broken on 2.3.246, 22.214.171.1246-pre6, and latest nightly 126.96.36.199
I cannot confirm the initial report as it's working fine and I don't have iOS 7. It also sounds like another issue we fixed.
Paul's report can be reproduced. To reiterate, the issue isn't apparent at the NavigationBar, but the TabBar.
Migrated to https://github.com/xamarin/Xamarin.Forms/issues/1426
Please subscribe to that issue for future updates.